This application supports a renewal of the Mid-career Investigator (K24) Award in Patient-Oriented Research from the NIA to Thomas Gill, MD, a geriatrician and epidemiologist who has been on the faculty at Yale since 1994. During the first 4 years of this award, Dr. Gill has been the primary or secondary mentor to 14 junior investigators. Significant accomplishments during the current funding period include a dramatic increase in the number of senior-authored (from 2 to 14) and first-authored (from 9 to 16) reports, receipt of 8 career development awards by Dr. Gill's trainees, renewal of Dr. Gill's first R01 with MERIT Award designation, receipt of a second R01, and expansion of Dr. Gill's research program to include large-scale clinical trials. Dr. Gill's long-term career objective is to build a premier program in patient-oriented research related to disability and disabling disorders. The specific aims of this competitive renewal are to complete the proposed research projects and to further strengthen and expand Dr. Gill's formal mentorship program for junior investigators, which he successfully established during the initial funding period. Dr. Gill's mentorship program is designed to attract junior investigators, across disciplines, who are pursuing patient-oriented aging research related to disability and disabling disorders. This includes functional assessment in general as well as the functional consequences of highly prevalent disease-specific conditions such as arthritis, heart disease, and depression (among others). By addressing fundamental issues related to the epidemiology and prevention of disability, Dr. Gill's internationally recognized research program provides a superb platform for his greatly expanded mentorship program, which includes didactic training, hands-on research training, and a research infrastructure. The Yale environment provides the ideal setting, replete with interdisciplinary research and training programs, to foster Dr. Gill, the proposed research projects, and the mentorship program. Successful renewal of the K24 Award will strengthen and expand the infrastructure for Dr. Gill's mentorship program, create new opportunities for his trainees to actively participate in large-scale research projects, provide resources for pilot studies, and facilitate Dr. Gill's ongoing career development. Dr. Gill envisions continued growth of his research and mentorship program over the next several years, culminating in a new Center for Disability and Disabling Disorders.